OBJECTIVE: To review reliability, validity, and normative data from 7 different studies, involving a total of 1,988 people with diabetes, and provide a revised version of the Summary of Diabetes Self-Care Activities (SDSCA) measure. RESEARCH DESIGN AND METHODS: The SDSCA measure is a brief self-report questionnaire of diabetes self-management that includes items assessing the following aspects of the diabetes regimen: general diet, specific diet, exercise, blood-glucose testing, foot care, and smoking. Normative data (means and SD), inter-item and test-retest reliability, correlations between the SDSCA subscales and a range of criterion measures, and sensitivity to change scores are presented for the 7 different studies (5 randomized interventions and 2 observational studies). RESULTS: Participants were typically older patients, having type 2 diabetes for a number of years, with a slight preponderance of women. The average inter-item correlations within scales were high (mean = 0.47), with the exception of specific diet; test-retest correlations were moderate (mean = 0.40). Correlations with other measures of diet and exercise generally supported the validity of the SDSCA subscales (mean = 0.23). CONCLUSIONS: There are numerous benefits from standardization of measures across studies. The SDSCA questionnaire is a brief yet reliable and valid self-report measure of diabetes self-management that is useful both for research and practice. The revised version and its scoring are presented, and the inclusion of this measure in studies of diabetes self-management is recommended when appropriate.